Method and system for cleaning a frequency band

Abstract

A cable system (10) has a plurality of CAUs (34) coupled to a variety of network devices (58-68) in the subscriber's premise (36). The network devices (58-68) transmit signals to the CAU (34) in a clear frequency (100). The signals are coupled to a filter (70) which blocks any ingress noise from the premise (36). The filter (70) is coupled to a mixer (76), which down converts the signals from the clear frequency (100) to a desired frequency (104). Upstream signals in a bypass band (102) are coupled from the network devices to a low pass filter (72). The signals are then combined with the downconverted signals and transmitted into the cable system (10).

What is claimed is: 
     
       1. A system comprising: a cable access unit receiving information transmitted in a clear frequency spectrum from an interactive network device located at a subscriber premise through a cable over a first channel;   a filter in the cable access unit coupled to the cable, the filter blocking energy in a desired frequency band on a communication network; and   a frequency shifter coupled to the filter shifting the first channel to a second channel in the desired frequency band for upstream transmission through the communication network to a cable headend.   
     
     
       2. A system according to claim 1, the filter blocking energy in a desired frequency band in the communication network to reduce ingress noise in the communication network. 
     
     
       3. A system according to claim 2, the frequency shifter shifting the information to a plurality of channels within the desired frequency band. 
     
     
       4. A system according to claim 3, the cable access unit receiving information transmitted over a plurality of channels within the clear frequency spectrum. 
     
     
       5. A method comprising the steps of: receiving information transmitted in a clear frequency spectrum from an interactive network device located at a subscriber premise through a cable over a first channel;   blocking energy in a desired frequency band in a communication network;   shifting the first channel to a second channel in the desired frequency band; and   transmitting the information to a cable headend through the communication network over the second channel.   
     
     
       6. A method according to claim 5 wherein the step of blocking energy comprises blocking energy in a desired frequency band in the communication network to reduce ingress noise. 
     
     
       7. A method according to claim 6 wherein the step of shifting the information comprises shifting the information to a plurality of channels within the desired frequency band. 
     
     
       8. A method according to claim 7 wherein the step of receiving information comprises receiving information transmitted over a plurality of channels in the clear frequency spectrum. 
     
     
       9. A cable access unit comprising: a receiver receiving information transmitted in a clear frequency spectrum from an interactive network device located at a subscriber premise through a cable over a first channel;   a filter coupled to the receiver, the filter blocking energy in a desired frequency band in a communication network;   a frequency shifter coupled to the filter, the frequency shifter shifting the first channel to a second channel in the desired frequency band; and   a transmitter coupled to the frequency shifter, the transmitter transmitting to a cable headend through the communication network over the second channel.   
     
     
       10. A cable access unit according to claim 9, the filter blocking energy in a desired frequency band in the communication network to reduce ingress noise. 
     
     
       11. A cable access unit according to claim 10, the frequency shifter shifting the information to a plurality of channels within the desired frequency band. 
     
     
       12. A cable access unit according to claim 11 the receiver receiving information transmitted over a plurality of channels in the clear frequency spectrum. 
     
     
       13. A method comprising the steps of: receiving information transmitted in a clear frequency spectrum from an interactive network device located at a subscriber premise through a cable having a plurality of upstream and downstream channels in a communications network;   blocking energy in the plurality of upstream channels in the communication network;   shifting the information from a frequency band outside the plurality of upstream and downstream channels to at least one of the plurality of upstream channels; and   transmitting the information to a cable headend through the communication network.   
     
     
       14. A method according to claim 13 wherein the step of blocking energy comprises blocking energy in a desired frequency band in the communication network to reduce ingress noise. 
     
     
       15. A method according to claim 14 wherein the step of receiving information comprises receiving information transmitted over a plurality of channels in the clear frequency spectrum. 
     
     
       16. A cable access unit comprising: a receiver receiving information transmitted in a clear frequency spectrum from an interactive network device located at a subscriber premise through a cable having a plurality of upstream and downstream channels;   a filter coupled to the receiver, the filter blocking energy in the plurality of upstream channels in a communication network;   a frequency shifter coupled to the filter, the frequency shifter shifting the information from a frequency outside the plurality of upstream and downstream channels to at least one of the plurality of upstream channels; and   a transmitter coupled to the frequency shifter, the transmitter transmitting the information over at least one of the plurality of upstream channels to a cable headend through the communication network.   
     
     
       17. A cable access unit according to claim 16, the filter blocking energy in a desired frequency band on the communication network to reduce ingress noise. 
     
     
       18. A cable access unit according to claim 17, the receiver receiving information transmitted over a plurality of channels in the clear frequency spectrum. 
     
     
       19. A system comprising: a cable access unit receiving information transmitted over at least one of a plurality of channels outside a plurality of upstream and downstream channels from an interactive network device located at a subscriber premise through a cable having a plurality of upstream and downstream channels in a communication network;   a filter in the cable access unit coupled to the cable, the filter blocking energy in the plurality of upstream channels in the communication network to reduce ingress noise in the communication network; and   a frequency shifter coupled to the filter the frequency shifter shifting the at least one of the plurality of channels outside the plurality of upstream and downstream channels to at least one of the plurality of upstream channels for upstream transmission through the communication network to a cable headend.   
     
     
       20. A system according to claim 19 wherein the filter is coupled to the frequency shifter through a switch. 
     
     
       21. A system according to claim 19, the filter passing the clear frequency band and a selected bypass band. 
     
     
       22. A system according to claim 21 wherein signals within the selected bypass band are not frequency shifted. 
     
     
       23. A system according to claim 19 wherein the interactive network device is selected from the group consisting of a modem, a CATV set-top box, a utility management device, a video conference box, and a wireless radio port. 
     
     
       24. A method comprising the steps of: receiving information transmitted over a plurality of channels within a clear frequency spectrum from an interactive network device located at a subscriber premise through a cable over a first plurality of channels;   blocking energy in the second plurality of channels in a communication network to reduce ingress noise;   shifting the first plurality of channels to a second plurality of channels within the desired frequency band; and   transmitting the information to a cable headend through the communication network.   
     
     
       25. A method according to claim 24 wherein the interactive network device is selected from the group consisting of a modem, a CATV set-top box, a utility management device, a video conference box, and a wireless radio port. 
     
     
       26. A cable access unit comprising: a receiver receiving information transmitted over a plurality of channels within a clear frequency spectrum from an interactive network device located at a subscriber premise through a cable having a plurality of upstream and downstream channels in a communication network;   a filter coupled to the receiver, the filter permitting a downstream signal to be passed from a cable headend through the cable access unit to equipment in the subscriber premises while blocking energy in a desired frequency band to reduce ingress noise;   a frequency shifter coupled to the filter, the frequency shifter shifting the plurality of channels outside the plurality of upstream and downstream channels to the plurality of upstream channels; and   a transmitter coupled to the frequency shifter, the transmitter transmitting the information over the plurality of upstream channels to the cable headend through the communication network.   
     
     
       27. A system comprising: a cable access unit receiving information transmitted over a plurality of channels from an interactive network device located at a subscriber premise through a cable;   a filter in the cable access unit coupled to the cable, the filter permitting a downstream signal in a plurality of downstream channels to be passed from the cable headend through the cable access unit to equipment in the subscriber premises while blocking energy from a plurality of upstream channels in a communication network to reduce ingress noise in the communication network; and   a frequency shifter coupled to the filter, the frequency shifter shifting the plurality of channels outside the plurality of upstream and downstream channels to the plurality of upstream channels for upstream transmission through the communication network to a cable headend.   
     
     
       28. A system according to claim 27 wherein the filter in the cable access unit blocks the upstream signal in the plurality of upstream channels.